Fix found flaws of package constants

[Noremos]

Fix incorrect search in SCHEMAs list
Fix missing RDB$CONSTANT_SOURCE setup
Add USAGE privilage to SYSTEM packages

[aafemt]

Why not loop here?

[Noremos]

I followed the original style. Is loop worth it?

[Noremos]

Or do you mean storing each privilege in a separate record?

[aafemt]

No, I mean that the check and the way one string is assigned to another is strange, but if it was an original code... Probably, it still must be replaced with strncpy.

[Noremos]

Hm, as I can see, storing each privilege in a separate record is indead a correct way to do it

[aafemt]

In this case CHAR(6) field makes no sense.

[Noremos]

I found an issue related to metadata. When selecting a constant from a procedure, an error may occur:
Statement format outdated, need to be reprepared. I hope I can fix this soon.

Code to reproduce:

set term ^;

   CREATE PACKAGE TEST1
   AS
   BEGIN
       PROCEDURE P1(I INT) RETURNS (PROCEDURE_OUTPUT INT); -- public procedure
       CONSTANT TEST1_PACKAGE_CONSTANT INTEGER = 10;
   END^

   CREATE PACKAGE BODY TEST1
   AS
   BEGIN
       CONSTANT CP2 INTEGER = 15;
       CONSTANT CP3 INTEGER = 30;
       PROCEDURE P1(I INT) RETURNS (PROCEDURE_OUTPUT INT)
       AS
       BEGIN
           PROCEDURE_OUTPUT = TEST1.TEST1_PACKAGE_CONSTANT + TEST1.CP2;
           SUSPEND;
       END
   END ^

   set term ;^
   commit;

   -- Test Public
   select test1.TEST1_PACKAGE_CONSTANT from rdb$database ;
   select * from test1.p1(0);
   commit;

[hvlad]

storeMetaDataBlob() maybe ?

[Noremos]

Thanks for the advice. Changed as suggested